<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<input type="checkbox"  checked="checked" />
		<input type="checkbox"  checked=false />
		<input type="checkbox"  checked=null />
		<input type="checkbox"  checked=undefined />
		<input type="checkbox"  checked="" />
		<input type="checkbox"  checked />
		<input type="checkbox"   />
	</body>
</html>
